It's a gamble.
These prices are due to a shortage of physical out there to buy (for maples) at present. Drutter has been talking about supply in and around Vancouver dried up, so I am not surprised to see some enterprising individuals cashing in.
I can see regular supply of maples being back early in 2011 so if you can get a 50% increase on your sale price, I'd say go for it - you can easily convert your profit into localised silver at a profit.
Maples are not numismatics (well most are not), so if people are willing to pay a premium, then why say no?